The Bit and the Pendulum

Tom Siegfried

Description

"Funny, clear, deep, and right on target. [Siegfried] lets us get a handle on ideas that are essential for understanding the evolving world."
-K. C. Cole, author of The Universe and the Teacup
"An eager, ambitious book. A stimulating, accessible introduction to scientific theory."
-Dallas Morning News
An award-winning journalist surveys the horizon of a new revolution in science
Everything in the universe, from the molecules in our bodies to the heart of a black hole, is made up of bits of information. This is the radical idea at the center of the new physics of information, and it is leading to exciting breakthroughs in a vast range of science, including the invention of a new kind of quantum computer, millions of times faster than any computer today. Acclaimed science writer Tom Siegfried offers a lively introduction to the leading scientists and ideas responsible for this exciting new scientific paradigm.

Sujets

• Quantum Theory
• Quantum Computing
• Sciences et techniques
• Quantum computer
• Physics
• M-theory
• Science
• Physique
• Physical attractiveness

Informations

• Publié par: Turner Publishing Company
• Date de parution: 02 mai 2008
• Nombre de lectures: 0
• EAN13: 9780470354230
• Langue: English

Extrait

T HE B IT AND THE P ENDULUM
From Quantum Computing to M Theory - The New Physics of Information
Tom Siegfried

John Wiley Sons, Inc.
New York Chichester Weinheim Brisbane Singapore Toronto
Copyright 2000 by Tom Siegfried. All rights reserved
Published by John Wiley Sons, Inc.
Published simultaneously in Canada
No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, [phone], fax [phone]. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley Sons, Inc., 605 Third Avenue, New York, NY 10158-0012, [phone], fax [phone], email: [e-mail].
This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional person should be sought.
Library of Congress Cataloging-in-Publication Data:
Siegfried, Tom.
The bit and the pendulum : from quantum computing to m theory-the new physics of information / Tom Siegfried.
p. cm.
Includes index.
ISBN 0-471-32174-5 (cloth : alk. paper)
ISBN 0-471-39974-4 (paper)
1. Computer science. 2. Physics. 3. Information technology. I. Title.
QA76.S5159 1999

004-dc21
99-22275
10 9 8 7 6
Contents
Preface
Introduction
1 Beam Up the Goulash
2 Machines and Metaphors
3 Information Is Physical
4 The Quantum and the Computer
5 The Computational Cell
6 The Computational Brain
7 Consciousness and Complexity
8 IGUSes
9 Quantum Reality
10 From Black Holes to Supermatter
11 The Magical Mystery Theory
12 The Bit and the Pendulum
Notes
Glossary
Further Reading
Index
Preface
In the course of my job, I talk to some of the smartest people in the universe about how the universe works. These days more and more of those people think the universe works like a computer. At the foundations of both biological and physical science, specialists today are construing their research in terms of information and information processing.
As science editor of the Dallas Morning News, I travel to various scientific meetings and research institutions to explore the frontiers of discovery. At those frontiers, I have found, information is everywhere. Inspired by the computer as both tool and metaphor, today s scientists are exploring a new path toward understanding life, physics, and existence. The path leads throughout all of nature, from the interior of cells to inside black holes. Always the signs are the same: the world is made of information.
A few years ago, I was invited to give a talk to a regional meeting of MENSA, the high-IQ society. I decided to explore this theme, comparing it to similar themes that had guided the scientific enterprise in the past. For it seemed to me that the role of the computer in twentieth-century science was much like that of the steam engine in the nineteenth century and the clock in medieval times. All three machines were essential social tools, defining their eras; all three inspired metaphorical conceptions of the universe that proved fruitful in explaining many things about the natural world.
Out of that talk grew this book. It s my effort to put many pieces of current science together in a picture that will make some sense, and impart some appreciation, to anyone who is interested.
Specialists in the fields I discuss will note that my approach is to cut thin slices through thick bodies of research. No doubt any single chapter in this book could easily have been expanded into a book of its own. As they stand, the chapters that follow are meant not to be comprehensive surveys of any research area, but merely to provide a flavor of what scientists at the frontiers are up to, in areas where information has become an important aspect of science.
Occasional passages in this book first appeared in somewhat different form in articles and columns I ve written over the years for the Dallas Morning News. But most of the information story would never fit in a newspaper. I ve tried to bring to life here some of the subtleties and nuances of real-time science that never make it into the news, without bogging down in technicalities.
To the extent I ve succeeded in communicating the ideas that follow, I owe gratitude to numerous people. Many of the thoughts in this book have been shaped over the years through conversations with my longtime friend Larry Bouchard of the University of Virginia. I ve also benefited greatly from the encouragement, advice, and insightful questions over dinner from many friends and colleagues, including Marcia Barinaga, Deborah Blum, K. C. Cole, Sharon Dunwoody, Susan Gaidos, Janet Raloff, JoAnn Rodgers, Carol Rogers, Nancy Ross-Flanigan, Diana Steele, and Jane Stevens.
I must also express deep appreciation for my science journalist colleagues at the Dallas Morning News: Laura Beil, Sue Goetinck, Karen Patterson, and Alexandra Witze, as well as former News colleagues Matt Crenson, Ruth Flanagan, Katy Human, and Rosie Mestel.
Thanks also go to Emily Loose, my editor at Wiley; my agent, Skip Barker; and of course my wife, Chris (my harshest and therefore most valuable critic).
There are in addition countless scientists who have been immensely helpful to me over the years, too many to attempt to list here. Most of them show up in the pages that follow.
But I sadly must mention that the most helpful scientist of all, Rolf Landauer of IBM, did not live to see this book. He died in April 1999, shortly after the manuscript was completed. Landauer was an extraordinary thinker and extraordinary person, and without his influence and inspiration I doubt that this book would have been written.
Tom Siegfried
May 1999
Introduction
I think of my lifetime in physics as divided into three periods. In the first period . . . I was in the grip of the idea that Everything is Particles. . . . I call my second period Everything is Fields. . . . Now I am in the grip of a new vision, that Everything is Information.
-JOHN ARCHIBALD WHEELER, Geons, Black Holes, and Quantum Foam
John Wheeler likes to flip coins.
That s not what he s famous for, of course. Wheeler is better known as the man who named black holes, the cosmic bottomless pits that swallow everything they encounter. He also helped explain nuclear fission and is a leading expert on both quantum physics and Einstein s theory of relativity. Among physicists he is esteemed as one of the greatest teachers of the century, his students including Nobel laureate Richard Feynman and dozens of other prominent contributors to modern science.
One of Wheeler s teaching techniques is coin tossing. I remember the class, more than two decades ago now, in which he told all the students to flip a penny 50 times and record how many times it came up heads. He taught about statistics that way, demonstrating how, on average, heads came up half the time, even though any one run of 50 flips was likely to turn up more heads than tails, or fewer. *
Several years later, Wheeler was flipping coins again, this time to help an artist draw a picture of a black hole. Never mind that black holes are invisible, entrapping light along with anything else in their vicinity. Wheeler wanted a special kind of picture. He wanted it to illustrate a new idea about the nature of information.
As it turns out, flipping a coin offers just about the simplest possible picture of what information is all about. A coin can turn up either heads or tails. Two possibilities, equally likely. When you catch the coin and remove the covering hand, you find out which of the two possibilities it is. In the language that computers use to keep track of information, you have acquired a single bit.
A bit doesn t have to involve coins. A bit can be represented by a lightbulb-on or off. By an arrow, pointing up or down. By a ball, spinning clockwise or counterclockwise. Any choice from two equally likely possibilities is a bit. Computers don t care where a bit comes from-they translate them all into one of two numbers, 0 or 1.
Wheeler s picture of a black hole is covered with boxes, each containing either a zero or a one. The artist filled in the boxes with the numerals as a student tossed a coin and called out one for heads or zero for tails. The resulting picture, Wheeler says, illustrates the idea that black holes swallow not only matter and energy, but information as well.
The information doesn t have to be in the form of coins. It can be patterns of ink on paper or even magnetic particles on a floppy disk. Matter organized or structured in any way contains information about how its parts are put together. All that information is scrambled in a black hole s interior, though-incarcerated forever, with no possibility of parole. As the cosmologist Rocky Kolb describes the situation, black holes are like the Roach Motel. Information checks in, but it doesn t check out. If you drop a coin into a black hole, you ll never know whether it lands heads or tails.
But Wheeler observes that the black hole keeps a record of the information it engulfs. The more information swallowed, the bigger the black hole is-and thus the more space on the black hole s surface to accommodate boxes depicting bits. To Wheeler, this realization is curious and profound. A black hole can consume anything that exists and still be described in terms of how much information it has digested. In other words, the black